The National Day of RomaniaThe national holiday of Romania, the Union Day (also called Unification Day) occurring on December 1, commemorates the assembly of the delegates of ethnic Romanians held in Alba Iulia, which declared the Union of Transylvania with Romania. This holiday, set after the 1989 Romanian Revolution, marks the unification not only of Transylvania, but also of the provinces of Banat, Bessarabia and Bukovina with the Romanian Kingdom, in 1918, the Union of Transylvania with Romania being the last event, sealing the unification of the country.

The Old KingdomThe 1859 ascendancy of Alexander John Cuza as prince of both Moldavia and Wallachia under the nominal suzerainty of the Ottoman Empire united an identifiably Romanian nation under a single ruler. On February 5, 1862 (January 24 Old Style) the two principalities were formally united to form Romania, with Bucharest as its capital.In 1877, following a Russian-Romanian-Turkish war, Romania was recognized as independent by the Treaty of Berlin, 1878, and acquired Dobruja, although she was forced to surrender southern Bessarabia (Budjak) to Russia. Charles was crowned as Carol, the first King of Romania, in 1881.

Union of Besserabia with RomaniaWorld War I brought in a rise in political and cultural (national) awareness of the locals, as 300,000 Bessarabians enrolled in the Russian Army formed in 1917, within bigger units several "Moldavian Solders' Committees". Following the Russian Revolution of 1917, Bessarabia elected its own parliament, Sfatul Ţării (October-November 1917), which opened on December 3 1917, proclaimed the Moldavian Democratic Republic (December 15 1917), formed its government (December 21 1917), proclaimed independence from Russia (February 6 1918), and on April 9 1918, Sfatul Ţării decided with 86 votes for, 3 against and 36 abstaining, towards the union with the Kingdom of Romania, conditional upon the fulfillment of the agrarian reform, local autonomy, and respect for universal human rights. The county councils of Bălţi, Soroca and Orhei were the earliest to ask for unification with the Kingdom of Romania, and on April 9 1918, Sfatul Ţării voted in favour of the union.

Union of Bukovina with RomaniaWith the collapse of Austria-Hungary in 1918, both the local Romanian National Council and the Ukrainian National Council based in Galicia claimed the region. A Constituent Assembly on 14/27 October 1918 formed an Executive Committee, to whom the Austrian governor of the province handed power. The Executive Committee called a General Congress of Bukovina for 15/28 November 1918, where 74 Romanians, 13 Ruthenians, 7 Germans, and 6 Poles were elected (this is the linguistic composition, and Jews were not recorded as a separate group). A popular enthusiasm sprang throughout the region, and a large number of people gathered in the city to wait for the resolution of the Congress.

Union of Transsylvania with RomaniaOn December 1, 1918 (November 18 Old Style), the National Assembly of Romanians of Transylvania and Hungary, consisting of 1,228 elected representatives of the Romanians in Transylvania, Banat, Crişana and Maramureş, convened in Alba Iulia and decreed (by unanimous vote)

“the unification of those Romanians and of all the territories inhabited by them with Romania.”

The Resolution voted by the National Assembly stipulated also the "fundamental principles for the foundation of the new Romanian State":

1. Full national freedom for all the co-inhabiting peoples. Each people will study, manage and judge in its own language by individual of its own stock and each people will get the right to be represented in the law bodies and to govern the country in accordance with the number of its people. 2. Equal rights and full autonomous religious freedom for all the religions in the State. 3. Full democratic system in all the realms of public life. Suffrage universal, direct, equal, secret, in each commune, proportionally, for both sexes, 21 years old at the representation in communes, counties or parliament. 4. Full freedom of the press, association and meeting, free propaganda of all human thoughts. 5. Radical agrarian reform. All the assets, above all the big ones, will be inscribed. The wills by which the heir consigns the land to a third party will be abolished; meanwhile, on the basis of the right to cut down estates freely, the peasant will be able to his own property (ploughing land, pasture, forest), at least one for him and his family to labour on. The guiding principle of this agrarian policy is promoting social evening, on the one hand, and giving force to production, on the other. 6. The industrial workers will be granted the same rights and privileges that are in force in the most advanced western industrial states.

The union was conditional, and demanded the preservation of a democratic local autonomy, the equality of all nationalities and religions.The Assembly also formed from 200 of its members, plus 50 co-opted members a High National Romanian Council of Transylvania, the new permanent parliament of Transylvania. The next day, on December 2, 1918 the High National Romanian Council of Transylvania formed a government under the name of Directory Council of Transylvania (Consiliul Dirigent al Transilvaniei), headed by Iuliu Maniu.

On December 11, 1918, King Ferdinand signed the Law regarding the Union of Transylvania, Banat, Crişana, the Satmar and Maramureş with the Old Kingdom of Romania, decreeing that

“The lands named in the resolution of the Alba-Iulia National Assembly of the 18th of November 1918 are and remain forever united with the Kingdom of Romania.”